Allen-Bradley Powermonitor 3000 User Manual page 85

Communications 4-25
The RS-485 communications standard supports multi-drop
communications between a master station and up to 31 slaves on a
single network up to 1219 meters (4000 feet) long. For satisfactory
communications performance, however, we recommend connecting
no more than 8 to 12 Powermonitor 3000 units to an RS-485
multi-drop network.
The optional RS-232 communications port has several configuration
settings that support the use of modems for point-to-point and
point-to-multipoint communications. You may select Hardware
Handshaking (CTS/RTS) and adjust the Delay parameter to match
your choice of modem hardware. Please refer to Configuring Optional
RS-232 Communications for detailed information on these settings.
The Powermonitor 3000 does not initiate messages nor does it support
modem dial-out capabilities.
Allen-Bradley DF1 protocol
The Allen-Bradley DF1 half-duplex slave protocol is supported by a
number of Rockwell Automation and third party products. Please refer
to publication 1770-6.5.16, DF1 Protocol and Command Set Reference
Manual, for further information.
The Powermonitor 3000 serial ports do not support DF1 full-duplex
communications or Data Highway 485 (DH-485) communications.
The network master device must be configured as a DF1 polling
master. All devices on the network must be set to the same baud rate.
The node addresses of the Powermonitor 3000 units must be listed in
a permanent or temporary polling list of the master device, and the
error checking must be set to CRC. When communications is
established, the RS-485 or RS-232 RX and TX status LEDs will flash
alternately at a rapid rate. If you are using Rockwell Software
TM
RSLinx as a polling master, the Powermonitor 3000 will appear in
TM
RSWho if it is defined in the polling list. For best communications
performance using RSLinx, keep the number of concurrent clients to a
minimum (for example, turn off the auto-browse function in RSWho).
To communicate with an Allen-Bradley PLC-5, SLC 500 or
ControlLogix controller, use message instructions that address the DF1
master port number, the Powermonitor 3000 node address, the
Powermonitor 3000 data table address, (e.g. F17:0 - Metering Power
Results), and the length of the file in elements. The target file must be
of the same data type as the Powermonitor 3000 data table, e.g.
integer or floating-point.
Allen-Bradley HMIs
Publication 1404-UM001D-EN-E - October 2004